Water, forests and fishing

Last time

Before we start: last time, in Mineral resources and fossil fuels, you learned these points. Here they are again on one card. Keep them in mind, because today builds on them.

Living resources

Pakistan depends on one great river system for almost all its farming and much of its power. Its forests are few but valuable, and its sea and rivers provide fish. This lesson covers water supply, forests and fishing.

The Indus River system

The Indus and its tributaries, the Jhelum, Chenab, Ravi, Sutlej and Beas, supply most of Pakistan's water. The rivers are fed by monsoon rain and by melting snow and glaciers in the north. Under the Indus Waters Treaty of 1960, India uses the eastern rivers, and Pakistan the western rivers: the Indus, Jhelum and Chenab.

Dams and barrages

A dam stores water in a reservoir: Tarbela on the Indus and Mangla on the Jhelum are the largest. Dams also generate hydro-electric power. A barrage raises the river level and diverts water into canals for irrigation. Link canals carry water from the western rivers to areas once fed by the eastern rivers.

Problems with water supply

Reservoirs fill with silt, so they store less water over time. A growing population and farming need more water, and much is lost from unlined canals. Groundwater is pumped by tubewells faster than it is replaced, so water tables fall.

Forests and natural vegetation

Coniferous forests of pine and fir grow on the northern mountains. Riverine forests grow along the rivers, and irrigated plantations such as Changa Manga were planted by people. Mangrove forests grow in the Indus delta on the coast, and scrub forest covers drier areas.

Why forests matter

Forests give timber, firewood, resin and fodder. Trees protect soil from erosion, reduce floods, and slow the silting of reservoirs. Mangroves protect the coast from storms and are nurseries for fish and shrimps.

Deforestation and afforestation

Pakistan has little forest cover. Trees are cut for firewood, timber and farmland faster than they regrow. This causes soil erosion, landslides, floods and loss of wildlife. Afforestation means planting new forests, to protect soil and water, supply timber, and fight climate change. Large tree-planting campaigns have been run.

Fishing

Marine fishing takes place along the coast of Sindh and Balochistan, from harbours such as Karachi, Gwadar and Pasni. Shrimps are a valuable export. Inland fishing takes place in rivers, lakes, reservoirs and fish farms. Problems: over-fishing, pollution, and poor storage and processing.

Subsistence and commercial fishing

Subsistence fishing uses small boats and simple nets, mainly to feed the fisherman's family, with any extra sold locally. Commercial fishing uses large trawlers with engines, sonar and refrigeration, to catch large amounts for sale and export. Commercial fishing catches more, but can over-fish and damage the sea bed.

Mistakes that lose marks

Mistake one: confusing a dam with a barrage. Mistake two: saying Pakistan uses the eastern rivers under the treaty. Mistake three: listing effects of deforestation without developing them. The fix: precise terms, and each point developed.

The full-marks tip

The full-marks tip: a dam stores water; a barrage diverts it into canals. When asked to develop, follow each point with its consequence.

On one card

So, on one card: water, forests and fishing. Keep it for revision.